Overlapping stacked die package with vertical columns

ABSTRACT

Some forms relate to an electronic assembly that includes a die that includes an upper surface and a conductive column extending from the upper surface such that the conductive column is not surrounded by any material other than where the conductive column engages the die. Other forms relate to an electronic package that includes a stack of electronic assemblies where each electronic assembly includes a die that having an upper surface and a plurality of conductive columns extending from the upper surface such that each conductive column is not surrounded by any material other than where the conductive column engages the die, and wherein the stack of electronic assemblies is arranged in an overlapping configuration such the plurality of conductive columns on each electronic assembly are not covered by another electronic assembly.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.15/509,416, which is a U.S. National Stage Filing under 35 U.S.C. 371from International Application No. PCT/CN2014/088096, filed on 3 Oct.2014, and plublished as WO 2016/049940 A1 on 7 Apr. 2016, whichapplication is incorporated herein by reference in its entirety.

TECHNICAL FIELD

Embodiments described herein generally relate to stacked die packages,and more particularly to overlapping stacked die packages that includeconductive columns.

BACKGROUND

Mobile products (e.g., mobile phones, smart phones, tablet computers,etc.) are very restricted in available space because there are typicallysevere limitations for chip/package area and height (among otherphysical and electrical parameters). Therefore, it is extremelyimportant to reduce the size of electronic components (e.g., packagedchips or discrete devices, integrated passive devices (IPDs), surfacemount devices (SMDs), etc.) on a system board (e.g., printed circuitboard PCB).

Conventional stacked electronic components typically require relativelylarge z-height making them more difficult to fit inside a housing ofmobile products, especially when several chips, IPDs or SMDs need to beassembled and/or stacked one on top of another. In addition, as withmost electronic components, there is usually the goal of increasedelectrical performance.

There are two existing packaging methods for high die count stacked diepackages. One method forms a wire bond based package in which substrateand over mold add extra z-height to the package. In addition, wire bondbased package are also typically limited in their performance because ofthe number and length of the wires that are utilized in the packages.

Another existing packaging method for high die count stacked diepackages utilizes Thru Silicon Via (TSV) technology. High die countstacked die packages that utilize TSV usually have relatively highspeed. However, z-height reduction is still difficult with TSV. Inaddition, the vias that are formed using TSV technology often use upvaluable space on silicon. There are also usually relatively highmanufacturing costs that are associated with utilizing TSV technologymaking it more expensive to produce high die count stacked die packagesusing TSV technology. The typical z-height of a conventional 16 Die BGAstacked die package is 1.35 mm where each die is thinned to 35 um.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of an example die.

FIG. 2 is a side view of the example die shown in FIG. 1 with at leastone conductive column formed on the die.

FIG. 3 is an enlarged side view of the conductive column shown in FIG.2.

FIG. 4 is a top view of the die shown in FIG. 2.

FIG. 5 is a side view of a package that includes an overlapping stack ofelectronic assemblies.

FIG. 6 is a top view of the package shown in FIG. 5.

FIG. 7 is a side view of package shown in FIGS. 5 and 6 where theoverlapping stack of dies is enclosed in a mold.

FIG. 8 is a side view of the package shown in FIG. 7 where a portion ofthe mold has been removed to expose the columns on overlapping stack ofdies.

FIG. 9 is a side view of the package shown in FIG. 8 where aredistribution layer is placed on the exposed columns of the overlappingstack of dies.

FIG. 10 is a side view of the package shown in FIG. 9 where solder bumpsare placed on the redistribution layer of the overlapping stack of dies.

FIG. 11 is a side view of the package shown in FIG. 10 where a similaradditional package is inverted and aligned with the solder balls on thepackage shown in FIG. 10.

FIG. 12 is a flow diagram illustrating a method of overlapping a stackof electronic assemblies to form an electronic package.

FIG. 13 is block diagram of an electronic apparatus that includes theelectronic assemblies and/or the electronic packages described herein.

FIG. 14 is a side view of another electronic apparatus.

DESCRIPTION OF EMBODIMENTS

The following description and the drawings sufficiently illustratespecific embodiments to enable those skilled in the art to practicethem. Other embodiments may incorporate structural, logical, electrical,process, and other changes. Portions and features of some embodimentsmay be included in, or substituted for, those of other embodiments.Embodiments set forth in the claims encompass all available equivalentsof those claims.

Orientation terminology, such as “horizontal,” as used in thisapplication is defined with respect to a plane parallel to theconventional plane or surface of a wafer or substrate, regardless of theorientation of the wafer or substrate. The term “vertical” refers to adirection perpendicular to the horizontal as defined above.Prepositions, such as “on,” “side” (as in “sidewall”), “higher,”“lower,” “over,” and “under” are defined with respect to theconventional plane or surface being on the top surface of the wafer orsubstrate, regardless of the orientation of the wafer or substrate.

The electronic assemblies, packages and methods described herein mayaddress the drawbacks that are associated with using wire bond packagingtechnology and TSV technology to form high die count stacked diepackages. In addition, electronic assemblies, packages and methodsdescribed herein may increase the electrical performance of high diecount stacked die packages.

The electronic assemblies, packages and methods described herein mayprovide some benefits over using conventional TSV technology to formhigh die count stacked die packages.

First, smaller die to die standoff/space may be achieved. ConventionalTSV technology usually creates a standoff that is tens of microns, whilethe assemblies, packages and methods described herein may create astandoff that is 5 um and less. This smaller standoff may reduce theoverall size and thickness of the high die count stacked die packages.

Second, the silicon utilization efficiency of the electronic assemblies,packages and methods described herein may be higher than TSV technologybecause TSV technology must fabricate the vias through peripheral areasof silicon. This need to fabricate openings in the silicon to createopenings for via formation (i) uses valuable space on the silicon; and(ii) increases the fabrication costs associated with forming high diecount stacked die packages. The electronic assemblies, packages andmethods described herein do not require any type of fabrication tocreate openings in the silicon for vias.

Finally, the electronic assemblies, packages and methods describedherein may utilize existing wire bond equipment to create conductivecolumns on an upper surface of a die. This ability to potentially useexisting wire bond equipment may reduce the costs that are associatedwith fabricating the electronic assemblies, packages and methodsdescribed herein.

The electronic assemblies, packages and methods described herein mayprovide some benefits over using conventional substrate based wire bondtechnology.

First, the electronic assemblies, packages and methods described hereinmay provide improved electrical performance. The electrical performancemay be better because the conductive columns are shorter than the wiresthat are used in conventional wire bond technology.

Second, the overall size of the electronic assemblies, packages andmethods described herein may be much smaller than substrate basedpackage that utilize conventional wire bond technology. The overall sizemay be reduced because (i) the X-Y space on the substrate that isusually required for wire bonding may be saved; (ii) the extra overmolding that is usually required for the conductive wires that are usedin wire bonding may be eliminated to reduce the z-height; and (iii) asubstrate is not required because no wire bonding is necessary.

FIG. 1 is a side view of an example die 11 while FIG. 2 is a side viewof the example die 11 shown in FIG. 1 with at least one conductivecolumn 13 formed on the die 11 to create an electronic assembly 10. FIG.3 is an enlarged side view of the conductive column 13 shown in FIG. 2while FIG. 4 is a top view of the electronic assembly 10 shown in FIG.2.

FIGS. 2-4 illustrate an electronic assembly 10 that includes a die 11(or some other form of electronic component) having an upper surface 12.The electronic assembly 10 further includes a conductive column 13 thatextends from the upper surface 12 such that the conductive column 13 isnot surrounded by any material other than where the conductive column 13engages the die 11.

As an example, the conductive column 13 may be several hundred um long.It should be noted the conductive columns 13 may not have as high of anaspect ratio as shown in the FIGS. (i.e., the conductive columns 13 arenot drawn to scale). An example range for the aspect ratio of theconductive columns 13 would be from 1 to 20.

In the example electronic assembly 10 that is shown in FIGS. 2-4, thedie 11 includes a conductive pad 14 such that the conductive column 13extends from the conductive pad 14 on the die 11. It should be notedthat the conductive pad 14 shown in FIGS. 1-4 is merely an example of aconductor that may be included on the upper surface 12 of the die 11 forengagement with the conductive column 13.

In addition, the conductive column 13 may include a spherical section 16that engages the conductive pad 14 and a cylindrical section 17 thatextends from the spherical section 16. It should be noted that otherforms are contemplated for the conductive column 13. The configurationand size of the conductive column 13 will depend in part on the overalldesign of the electronic assembly 10 as well as manufacturingconsiderations that are associated with fabricating the conductivecolumns 13 (among other factors).

As shown in FIG. 4, the conductive column 13 may be part of a pluralityof conductive columns 13 extending from the upper surface 12 such thateach conductive column 13 is not surrounded by any material other thanwhere the conductive columns 13 engage the die 11. In the exampleelectronic assembly 10 that is shown in FIG. 4, the plurality ofconductive columns 13 are aligned in a row near one edge 18 of the die11.

It should be noted that the plurality of conductive columns 13 may bearranged in any manner on the upper surface 12 of the die 11. Asexamples, the plurality of conductive columns 13 may be arranged in anL-shaped, C-shaped, or multiple row configuration on the upper surface12 of the die 11. The arrangement of the plurality of conductive columns13 on the upper surface 12 of the die 11 will depend in part on theoverall design of the electronic assembly 10 as well as manufacturingconsideration that are associated with fabricating the electronicassembly 10 (among other factors).

FIG. 5 is a side view of a package 19 that includes an overlapping stack20 of electronic assemblies 10 that are similar to the electronicassemblies 10 shown in FIGS. 2-4. FIG. 6 is a top view of theoverlapping stack of electronic assemblies 10 shown in FIG. 5.

The package 19 shown in FIGS. 5 and 6 includes a stack 20 of electronicassemblies 10 where each electronic assembly 10 includes a die 11 havingan upper surface 12 and a plurality of conductive columns 13 extendingfrom the upper surface 12 such that each conductive column 13 in thestack 20 is not surrounded by any material other than where theconductive column 13 engages the respective die 11. The stack 20 ofelectronic assemblies 10 is arranged in an overlapping configurationsuch the plurality of conductive columns 13 on each electronic assembly10 are not covered by another electronic assembly 10.

In the overlapping stack of electronic assemblies 10 shown in FIGS. 5and 6, the plurality of conductive columns 13 in each electronicassembly 10 are aligned in a row near one edge of the respective die 11that includes the corresponding plurality of conductive columns 13. Thisconfiguration of the plurality of conductive columns 13 in eachelectronic assembly 10 allows the stack 20 of electronic assemblies 10to be arranged in a shingles configuration. It should be noted that themanner in which the electronic assemblies 10 overlap to form a stack 20of electronic assemblies 10 will depend in part on how plurality ofconductive columns 13 are configured on each respective die 11.

The conductive columns 13 that extend from each die 11 may have same ordifferent aspect ratios. In addition, there may be a different number ofconductive columns 13 in each electronic assembly 10 that forms theelectronic package 19. It should be noted that the dies 11 in eachelectronic assembly 10 of the electronic package 1 may be the same, orhave a different size, thickness, material or function.

FIG. 7 is a side view of the overlapping stack 20 of dies 11 shown inFIGS. 5 and 6 where the package 19 is enclosed in a mold 21. As anexample, the mold 21 may surround the package 19 and be formed of athermoset molding compound, such as an epoxy (among other types ofmaterials). In some forms of the electronic package 19 a bottom surfaceof the bottom die 11 in the overlapping stack 20 of electronicassemblies 10 may be exposed (or not exposed as shown in FIG. 7)

FIG. 8 is a side view of the overlapping stack 20 of electronicassemblies 10 shown in FIG. 7 where a portion of the mold 21 has beenremoved to expose the plurality of conductive columns 13 on theelectronic package 19. As an example, the portion of the mold 21 may beremoved by grinding, although it should be noted that other materialremoval methods are contemplated. It should be noted that other forms ofthe package 19 are contemplated where a portion of the mold 21 may beremoved such that an upper surface 12 of the die 11 in the upper mostelectronic assembly 10 is exposed.

FIG. 9 is a side view of the example electronic package 19 shown in FIG.8 where a redistribution layer 22 may be placed on the exposed columns13 in the overlapping stack 20 of electronic assemblies 10. Theredistribution layer 22 may be placed on the exposed columns 13 in anymanner that is known now or discovered in the future. In addition, theconfiguration of the redistribution layer 22 will depend in part on thelocations of the exposed columns 13 in the overall design of theelectronic package 19.

FIG. 10 is a side view of the electronic package 19 shown in FIG. 9where solder bumps 23 may be placed on the conductive redistributionlayer 22 on the upper surface of the mold 21 and/or the exposed portionsof some of the plurality of conductive columns 13. The solder bumps 23may be placed on the conductive redistribution layer 22 and/or theexposed columns 13 in any manner that is known now or discovered in thefuture. In addition, the configuration of the solder bumps 13 willdepend in part on the locations of the exposed columns 13 andconfiguration of the redistribution layer 22 in the overall design ofthe package 19.

FIG. 11 is a side view of the package 19 shown in FIG. 10 where asimilar additional package 30 is inverted and aligned with the solderbumps 23 on the overlapping stack of dies shown in FIG. 10. It should benoted that although the package 19 is shown as being ready for assemblyto a second similar additional package 30 in FIG. 11, the package 19 maybe mounted using the solder bumps 23 (or some other type of conductor)to many other types of electronic devices (e.g., a substrate, die,chipset, motherboard, card and/or different type of electronic packageamong other types of electronic devices). In addition, the dies 11 orpackages 20 may be thinned (e.g., by grinding) in order to reduce theheight of the electronic assemblies 10 and/or packages 20. Example arealso contemplated where an additional electronic device (e.g., anotherpackage similar to electronic package 19) is mounted to the other sideof the electronic package 19 in order form a stack of multipleelectronic packages.

FIG. 12 is a flow diagram illustrating an example method [1200]. Themethod [1200] includes [1210] forming an electronic assembly 10 byattaching a conductive column 13 to an upper surface 12 of a die 11 suchthat the conductive column 13 extends from the upper surface 12 and isnot surrounded by any material other than where the conductive column 12engages the die 11 (see FIGS. 2 and 3). In some forms of the method[1200], attaching a conductive column 13 to an upper surface 12 of a die11 includes attaching a conductive column 13 to an upper surface 12 of adie 11 using wire bonding techniques, although any techniques that areknown now or discovered in the future may be used to attach theconductive column 13 to the upper surface 12 of the die 11.

As shown in FIG. 4, [1210] forming an electronic assembly 10 includesattaching a plurality of conductive columns 13 to an upper surface 12 ofa die 11 such that the conductive columns 13 extend from the uppersurface 12 and are not surrounded by any material other than where theconductive columns 13 engage the die 11. In some forms of the method[1200], attaching a plurality of conductive columns 13 to an uppersurface 12 of a die 11 includes aligning the plurality of conductivecolumns 13 in a row near one edge 18 of the die 11.

As shown in FIGS. 5 and 6, the method [1200] may further include [1220]stacking additional electronic assemblies 10 onto the electronicassembly 10 to form an electronic package 19. Each additional electronicassembly 10 includes a die 11 having an upper surface 12 and a pluralityof conductive columns 13 extending from the upper surface 12 such thateach conductive column 13 is not surrounded by any material other thanwhere the conductive columns 13 engage the respective dies 11. Theelectronic assemblies 10 that form the package 19 are arranged in anoverlapping configuration such the plurality of conductive columns 13 oneach electronic assembly 10 are not covered by another electronicassembly 10.

The method [1200] may further include [1230] forming a mold 21 thatsurrounds the stack 20 of electronic assemblies 10 (see FIG. 7). Inaddition, the method [1220] may include [1240] removing a portion of themold 21 to expose the conductive columns 13 through an upper surface ofthe mold 21 (see FIG. 8).

As shown in FIG. 9, the method [1200] may further include [1250] forminga conductive redistribution layer 22 on the upper surface of the mold21. In some forms of the method [1200] the conductive redistributionlayer 22 may engage an exposed portion of each of the plurality ofconductive columns 13. The method may also include [1260] forming solderbumps 23 on the conductive redistribution layer 22 or the exposedportions of some of the plurality of conductive columns 13 (see FIG.10).

Depending on the application where the package 19 is to be used, themethod [1200] may further include [1270] inverting the electronicpackage, and [1280] attaching the solder bumps 23 on the electronicpackage 19 to another electronic device (see, e.g., package 30 in FIG.11). The type of electronic device that the package 19 is attached towill depend in part on the desired functionality of the package 19 whenthe package 19 is used in a particular application.

It should be noted that while many of the electronic assemblies 10 andpackages 19 are shown as being in singulated form, the methods,electronic assemblies 10 and packages 19 described herein may be inwafer form, row form or any other form that promotes fabrication of theelectronic assemblies 10 and overlapping stacks 20 of electronicassemblies 10. The form taken by the methods, electronic assemblies 10and packages 19 will depend in part on manufacturing costs as well asthe overall desired functionality of the electronic assemblies 10 andpackages 19.

FIG. 13 is a block diagram of an electronic apparatus 1300 incorporatingat least one electronic assembly 10 and or electronic package 19described herein. Electronic apparatus 1300 is merely one example of anelectronic apparatus in which forms of the electronic assemblies 10,electronic packages 19 described herein may be used. Examples of anelectronic apparatus 1300 include, but are not limited to, personalcomputers, tablet computers, mobile telephones, game devices, MP3 orother digital music players, etc. In this example, electronic apparatus1300 comprises a data processing system that includes a system bus 1302to couple the various components of the electronic apparatus 1300.System bus 1302 provides communications links among the variouscomponents of the electronic apparatus 1300 and may be implemented as asingle bus, as a combination of busses, or in any other suitable manner.

An electronic apparatus 1300 as describe herein may be coupled to systembus 1302. The electronic apparatus 1300 may include any circuit orcombination of circuits. In one embodiment, the electronic apparatus1300 includes a processor 1312 which can be of any type. As used herein,“processor” means any type of computational circuit, such as but notlimited to a microprocessor, a microcontroller, a complex instructionset computing (CISC) microprocessor, a reduced instruction set computing(RISC) microprocessor, a very long instruction word (VLIW)microprocessor, a graphics processor, a digital signal processor (DSP),multiple core processor, or any other type of processor or processingcircuit.

Other types of circuits that may be included in electronic apparatus1300 are a custom circuit, an application-specific integrated circuit(ASIC), or the like, such as, for example, one or more circuits (such asa communications circuit 1314) for use in wireless devices like mobiletelephones, tablet computers, laptop computers, two-way radios, andsimilar electronic systems. The IC can perform any other type offunction.

The electronic apparatus 1300 may also include an external memory 1320,which in turn may include one or more memory elements suitable to theparticular application, such as a main memory 1322 in the form of randomaccess memory (RAM), one or more hard drives 1324, and/or one or moredrives that handle removable media 1326 such as compact disks (CD),flash memory cards, digital video disk (DVD), and the like.

The electronic apparatus 1300 may also include a display device 1316,one or more speakers 1318, and a keyboard and/or controller 1330, whichcan include a mouse, trackball, touch screen, voice-recognition device,or any other device that permits a system user to input information intoand receive information from the electronic apparatus 1300.

FIG. 14 illustrates an example apparatus 50 that includes a first die11′ and a first conductive column 17′ on a surface of the first die 11′.A second die 11″ is disposed adjacent the first die 11′ and a secondconductive column 17″ is on a surface of the second die 11″.

A mold material 21 contacts the first die 11′ and the second die 11″ ateach respective surface, and at each respective first conductive column17′ and second conductive column 17″. The mold material 21 exhibitscharacteristic flow across each of the first conductive column 17′ andthe second conductive column 17″, and wherein the mold material isintegral.

In some example forms of the apparatus 50, the apparatus 50 furtherincludes a subsequent die 11′″ and a subsequent conductive column 17′″on a surface of the subsequent die 11′″. The mold material 21 alsoexhibits characteristic residual flow across the subsequent conductivecolumn 17′″.

Conventional techniques for forming conducting columns typically includedrilling through a mold material to reach a die, and subsequentlyfilling in the drilled hole with conductive material to form theconductive column. Configurations that are formed by flowing a moldmaterial around already existing conducting columns will exhibitdistinctive physical characteristics that are detectable and differentfrom configurations formed by drilling and filling after the fact.Examples of such physical differences include, but are not limited tomicrostructural differences in a mold polymer or other material that isbent around the conductive column as a residual artifact from the flow.

One other example physical difference includes flow marks and weld linesin the mold 21. Weld lines represent an optical as well as mechanicaldefect in a molded part. Weld lines typically appear in the area wherethe polymer flows come together during the injection process.

Another example physical difference includes grooves. Grooves are asurface defect where “rings” appear at the surface of molded partsmainly around pin point gates and concentrically spreading over themolding. Jetting is a similar defect to grooves where rough or mattelines appear at the surface of the molding starting at the gate andspreading over the entire part.

Another example physical difference includes air streaks. Air streaks inmolded parts appear as matte, silvery or white lines (streaks) at thesurface of the molded parts. They can usually be found near domes, ribsand where the wall thickness of the molded part may vary. They also canappear near the sprue or near engraving and depressions.

To better illustrate the electronic assemblies, electronic packages andmethods disclosed herein, a non-limiting list of examples is providedherein:

Example 1 includes an electronic assembly that includes a die thatincludes an upper surface and a conductive column extending from theupper surface such that the conductive column is not surrounded by anymaterial other than where the conductive column engages the die.

Example 2 includes the electronic assembly of example 1, wherein the dieincludes a conductive pad such that the conductive column extends fromthe conductive pad on the die.

Example 3 includes the electronic assembly of any one of examples 1-2,wherein the conductive column includes a spherical section that engagesthe conductive pad and a cylindrical section that extends from thespherical section.

Example 4 includes the electronic assembly of any one of examples 1-3,wherein conductive column is part of a plurality of conductive columnsextending from the upper surface such that the conductive columns arenot surrounded by any material other than where the conductive columnsengage the die.

Example 5 includes the electronic assembly of any one of examples 1-4,wherein the plurality of conductive columns are aligned in a row nearone edge of the die.

Example 6 includes an electronic package that includes a stack ofelectronic assemblies where each electronic assembly includes a die thathaving an upper surface and a plurality of conductive columns extendingfrom the upper surface such that each conductive column is notsurrounded by any material other than where the conductive columnengages the die, and wherein the stack of electronic assemblies isarranged in an overlapping configuration such the plurality ofconductive columns on each electronic assembly are not covered byanother electronic assembly.

Example 7 includes the electronic package of example 6, wherein theplurality of conductive columns in each electronic assembly are alignedin a row near one edge of the respective die that includes thecorresponding plurality of conductive columns.

Example 8 includes the electronic package of any one of examples 6-7,and further including a mold that surrounds the stack of electronicassemblies.

Example 9 includes the electronic package of any one of examples 6-8,wherein a portion of the mold is removed to expose the conductivecolumns through an upper surface of the mold.

Example 10 includes the electronic package of any one of examples 6-9,and further including a conductive redistribution layer on the uppersurface of the mold, the conductive redistribution layer engaging anexposed portion of each of the plurality of conductive columns.

Example 11 includes the electronic package of any one of examples 6-10,and further including solder bumps that engage the conductiveredistribution layer on the upper surface of the mold or the exposedportions of some of the plurality of conductive columns.

Example 12 includes the electronic package of any one of examples 6-11,and further including an additional electronic package that is invertedand joined with the electronic package by connecting solder bumps on theelectronic package with solder bumps on the additional electronicpackage.

Example 13 is a method that includes forming an electronic assembly byattaching a conductive column to an upper surface of a die such that theconductive column extends from the upper surface and is not surroundedby any material other than where the conductive column engages the die.

Example 14 includes the method of example 13, wherein attaching aconductive column to an upper surface of a die includes attaching aconductive column to an upper surface of a die using wire bondingtechniques.

Example 15 includes the method of any one of examples 13-14, whereinforming an electronic assembly includes attaching a plurality ofconductive columns to an upper surface of a die such that the conductivecolumns extend from the upper surface and are not surrounded by anymaterial other than where the conductive columns engage the die.

Example 16 includes the method of any one of examples 13-15, whereinattaching a plurality of conductive columns to an upper surface of a dieincludes aligning the plurality of conductive columns in a row near oneedge of the die.

Example 17 includes the method of any one of examples 13-16, and furtherincluding stacking additional electronic assemblies onto the electronicassembly to form an electronic package, wherein each additionalelectronic assembly includes a die having an upper surface and aplurality of conductive columns extending from the upper surface suchthat each conductive column is not surrounded by any material other thanwhere the conductive column engages the respective die, and wherein theelectronic assemblies are arranged in an overlapping configuration suchthe plurality of conductive columns on each electronic assembly are notcovered by another electronic assembly.

Example 18 includes the method of examples 13-17, and further includingforming a mold that surrounds the stack of electronic assemblies.

Example 19 includes the method of any one of examples 13-18, and furtherincluding removing a portion of the mold to expose the conductivecolumns through an upper surface of the mold.

Example 20 includes the method of examples 13-19, and further includingforming a conductive redistribution layer on the upper surface of themold, wherein the conductive redistribution layer engages an exposedportion of each of the plurality of conductive columns, and formingsolder bumps on the conductive redistribution layer or the exposedportions of some of the plurality of conductive columns.

Example 21 includes the method of any one of examples 13-20, and furtherincluding inverting the electronic package, and attaching the solderbumps on the electronic package to another electronic device.

Example 22 includes an example apparatus that includes a first die and afirst conductive column on a surface of the first die. A second die isdisposed adjacent the first die and a second conductive column is on asurface of the second die. A mold material contacts the first die andthe second die at each respective surface, and at each respective firstconductive column and second conductive column. The mold materialexhibits characteristic flow across each of the first conductive columnand the second conductive column, and wherein the mold material isintegral.

Example 23 includes the apparatus of Example 22, and further includes asubsequent die and a subsequent conductive column on a surface of thesubsequent die. The mold material also exhibits characteristic residualflow across the subsequent conductive column.

This overview is intended to provide non-limiting examples of thepresent subject matter. It is not intended to provide an exclusive orexhaustive explanation. The detailed description is included to providefurther information about the methods.

The above detailed description includes references to the accompanyingdrawings, which form a part of the detailed description. The drawingsshow, by way of illustration, specific embodiments in which theinvention can be practiced. These embodiments are also referred toherein as “examples.” Such examples can include elements in addition tothose shown or described. However, the present inventors alsocontemplate examples in which only those elements shown or described areprovided. Moreover, the present inventors also contemplate examplesusing any combination or permutation of those elements shown ordescribed (or one or more aspects thereof), either with respect to aparticular example (or one or more aspects thereof), or with respect toother examples (or one or more aspects thereof) shown or describedherein.

In this document, the terms “a” or “an” are used, as is common in patentdocuments, to include one or more than one, independent of any otherinstances or usages of “at least one” or “one or more.” In thisdocument, the term “or” is used to refer to a nonexclusive or, such that“A or B” includes “A but not B,” “B but not A,” and “A and B,” unlessotherwise indicated. In this document, the terms “including” and “inwhich” are used as the plain-English equivalents of the respective terms“comprising” and “wherein.” Also, in the following claims, the terms“including” and “comprising” are open-ended, that is, a system, device,article, composition, formulation, or process that includes elements inaddition to those listed after such a term in a claim are still deemedto fall within the scope of that claim. Moreover, in the followingclaims, the terms “first,” “second,” and “third,” etc. are used merelyas labels, and are not intended to impose numerical requirements ontheir objects.

The above description is intended to be illustrative, and notrestrictive. For example, the above-described examples (or one or moreaspects thereof) may be used in combination with each other. Otherembodiments can be used, such as by one of ordinary skill in the artupon reviewing the above description.

The Abstract is provided to comply with 37 C.F.R. § 1.72(b), to allowthe reader to quickly ascertain the nature of the technical disclosure.It is submitted with the understanding that it will not be used tointerpret or limit the scope or meaning of the claims.

Also, in the above Detailed Description, various features may be groupedtogether to streamline the disclosure. This should not be interpreted asintending that an unclaimed disclosed feature is essential to any claim.Rather, inventive subject matter may lie in less than all features of aparticular disclosed embodiment. Thus, the following claims are herebyincorporated into the Detailed Description, with each claim standing onits own as a separate embodiment, and it is contemplated that suchembodiments can be combined with each other in various combinations orpermutations. The scope of the invention should be determined withreference to the appended claims, along with the full scope ofequivalents to which such claims are entitled.

1. An electronic package, comprising: a stack of electronic assemblieswhere each electronic assembly includes a die having an upper surfaceand a plurality of conductive columns extending from the upper surfacesuch that each conductive column is not surrounded by any material otherthan where the conductive column engages the die; wherein the stack ofelectronic assemblies is arranged in a stepped overlapping configurationsuch the plurality of conductive columns that extend from the uppersurface of each die on each electronic assembly are not covered byanother electronic assembly; and a mold that surrounds the stack ofelectronic assemblies, the conductive columns being exposed through anupper surface of the mold.
 2. The electronic package of claim 1, whereinthe plurality of conductive columns in each electronic assembly arealigned in a row near one edge of the respective die that includes thecorresponding plurality of conductive columns.
 3. The electronic packageof claim 1, further comprising a conductive redistribution layer on theupper surface of the mold, the conductive redistribution layer engagingan exposed portion of each of the plurality of conductive columns. 4.The electronic package of claim 3, further comprising solder bumps thatengage the conductive redistribution layer on the upper surface of themold or the exposed portions of some of the plurality of conductivecolumns.
 5. The electronic package of claim 4, further comprising anadditional electronic package that is inverted and joined with theelectronic package by connecting solder bumps on the electronic packagewith solder bumps on the additional electronic package.
 6. Theelectronic package of claim 1, wherein each of the dies in each of theelectronic assemblies includes conductive pads such that the pluralityof conductive columns extends from the conductive pads on the dies. 7.The electronic package of claim 6, wherein each of the conductivecolumns includes a spherical section that engages one of the conductivepads and a cylindrical section that extends from the spherical section.8. The electronic package of claim 1, wherein plurality of theconductive columns in each of the electronic assemblies have the samelength.
 9. A method comprising: forming an electronic assembly byattaching a plurality of conductive columns to an upper surface of a diesuch that the conductive columns extend from the upper surface; stackingadditional electronic assemblies onto the electronic assembly to form anelectronic package, wherein each additional electronic assembly includesa die having an upper surface and a plurality of conductive columnsextending from the upper surface such that each conductive column is notsurrounded by any material other than where the conductive columnengages the respective die, and wherein the electronic assemblies arearranged in an overlapping configuration such the plurality ofconductive columns on each electronic assembly are not covered byanother electronic assembly; and forming a mold that surrounds the stackof electronic assemblies.
 10. The method of claim 9, wherein attaching aplurality of conductive columns to an upper surface of a die includesattaching a plurality of conductive columns to an upper surface of a dieusing wire bonding techniques.
 11. The method of claim 9, whereinattaching a plurality of conductive columns to an upper surface of a dieincludes attaching the plurality of conductive columns to conductivepads on the die.
 12. The method of claim 11, wherein attaching theplurality of conductive columns to conductive pads on the die includesattaching a spherical section of each of the plurality of conductivecolumns to conductive pads on the die.
 13. The method of claim 9,wherein attaching a plurality of conductive columns to an upper surfaceof a die includes aligning the plurality of conductive columns in a rownear one edge of the die.
 14. The method of claim 9, further comprisingremoving a portion of the mold to expose the conductive columns throughan upper surface of the mold.
 15. The method of claim 14, furthercomprising: forming a conductive redistribution layer on the uppersurface of the mold, wherein the conductive redistribution layer engagesan exposed portion of each of the plurality of conductive columns; andforming solder bumps on the conductive redistribution layer or theexposed portions of some of the plurality of conductive columns.
 16. Themethod of claim 15, further comprising: inverting the electronicpackage; and attaching the solder bumps on the electronic package toanother electronic device.